The present invention is directed to computing devices. More particularly, the invention provides a keyboard apparatus and related methods having a backlighting characteristic for lighting one or more keys. Merely by way of example, the invention has been applied to a keyboard apparatus for a desk top computer, although it can also be applied to a laptop computer, modular computer, and other computing devices.
Computing devices have proliferated. In the early days, large mainframe computers dominated the computing landscape. These large mainframe computers were developed by companies such as IBM Corporation of Armonk, N.Y. Mainframe computers have been replaced, at least in part, by smaller computing devices, commonly known as “PCs.” PCs come in various shapes and sizes. PCs are often run using computer software such as XP™ from Microsoft Corporation from Redmond Wash. Other types of computer software come from Apple Computer of Cupertino, Calif. Smaller PC versions are often called “lap top computers.” Other types of PCs include larger desktop versions. Still other versions of PCs can be found in smaller devices such as personal digital assistants, called PDAs, cellular phones, and a variety of other applications.
All of these computing devices generally require input devices for human users to interact with them. As merely an example, computer keyboards are most commonly used as such input devices for inputting characters, numerals and symbols to electronic devices, particularly to these computing devices such as the PCs. While such keyboards are generally useful in lighted buildings, they may be difficult to use in a darker setting. As an example, such darker setting may be inside an airplane, which has been dimmed. Additionally, the larger setting may be in an unlighted building or other unlighted environment. To overcome these darker settings, certain keyboard devices have been lighted using various lighting techniques. These lighting techniques include use of individual light emitting diodes to emit light to individual key pads. Alternatively, light emitting crystals in the form of illuminating materials have been used to emit light to individual key pads. Various other techniques have been proposed.
As merely an example, a keyboard that uses backlighting is illustrated in U.S. Pat. No. 7,193,536 by Shipman (herein “Shipman”). FIG. 8 in Shipman discloses a keyboard housing 13; a plurality of key members 31, a biasing means (an elastic diaphragm 19) underlying said key members for biasing said key members in an upward direction, a substantially translucent circuit board 21 underlying said plurality of key members and said biasing means, and a luminescent planar sheet 49 for producing light. The luminescent planar sheet underlies the key members, the biasing means and the circuit board. Shipman requires use of an illuminating planar sheet, such as an electro-luminescent sheet using electroluminescent materials. In Shipman, luminescent planar sheet is an electro-luminescent panel lamp, which requires a luminescent material sandwiched between a pair of electrodes. Shipman also uses multiple light pipes embedded in a keyboard housing to propagate light to the key members. Unfortunately, Shipman has limitations, which will be described throughout the present specification and more particularly below.
From the above, it is seen that techniques for improving keyboards for computing devices are highly desirable.